ArklahomaCowboy

I apologize in advance. *Sorry* Obviously my search skills leave a lot to be desired. I’m sure this has already been addressed. I haven’t found it so I’m asking for some help.

My 1999 Cherokee fog/driving lights were broken & neglected for years while my daughter had this vehicle. When I got it back that was #1 OCD trigger that had to be addressed.

I bought quality fog lamp replacements. Then a new on/off switch when I realized it was bad. The lights worked great for a few months. Then I noticed the switch wasn’t switching the same, switch light burned out, then the switch stopped working. I replaced it, same result.

I know how to use a multi meter and a utilitarian grasp on electronics. Why is this happening? I have know idea what the power supply specs are supposed to be to and through the switch.

Wiring harness to lights tests good as far as I can tell.

I haven’t detected any shorts or grounding issues YET!

I leave it up to you…🤓

XJlimitedx99

This is a very very common issue. I have a pile of bad switches from when I was looking for a good one.

The problem is that the "On" indicator light that is inside the switch itself overheats and melts the switch. Fog lights are not intended to be used as fulltime driving lights, so they likely were not designed to be able to withstand the heat load of being on constantly.

The solution is to remove the bulb in the switch that illuminates when the lights are on.

ArklahomaCowboy

Thank you very much. Definitely a design flaw. I’ll see if I can rebuild one of the old ones. Thank you again.

UKXJ

XLlimitedx99 beat me to it, but they also suffer from bad connections (for the same reasons) & if that's the case it's more likely to be repairable. Not a difficult job, providing it's not too heat distorted, just a bit fiddly.

Another problem is most of the switches out there now are, not so cheap, copies &, therefore, of uncertain quality.

ArklahomaCowboy

Fortunately I have 3 switches to try to fix. The original and two replacements. I can definitely live without the switch light.

Seems to me if the light is already out. It’s a mater of cleaning the contacts, repairing the heat damage and even disconnecting the power to the light inside the switch. Should it want to re-illuminate.

Thank you for your response. It may take awhile to fix the switch. As I’m up to my *** in alligators with my “To Do” list at the moment.

I’ll keep you posted.

Ralph77

Like mentioned before the inside of the switch likes to melt.
I grab them here and there when at the boneyard so I always have extras.
When I need one I go in there, make sure it is not melted, clean it up, and install it.
Been running off my last one for quite sometime now.
And I run with my headlights and fog lights on always.
Shot of what it looks like when melted.
But also my '00 did not come with them.
So while some of the wiring was there they are wired up mostly like aftermarket one would be using a factory switch.
So that might have something to do with me not really having problems with them.

ArklahomaCowboy

It’s definitely a design flaw which should have been addressed. I drive with both as well and since my “99” has no daytime running lights. I use them for that as well.

So all the responses have been great and appreciated. Somewhere, I have a good used switch I’ve hidden from myself. I’m planning on installing it. But disconnecting the #1 wire to the switch. Which is supposed to be the indicator lamp power. Or find a LED to put in its place. On the assumption the stock light is some type of miniature incandescent light generating a lot of heat.

I’m also wondering if drilling a few vent holes in the top and sides would allow it to vent off the heat. I actually may try that if there’s enough room to cut some holes.

Thanks again

Nodak1

I ordered these when I changed the Fog Light switches I have to LED...

https://www.superbrightleds.com/neox...ment-panel-led

I got NEO3 and NEO4, but i'm not sure which is which anymore... One is for the ON lamp, and the other for Illumination with the dash lights. There's a bunch of color options as well as white.

They do have polarity, so if it doesn't work at first, flip it 180 deg.

UKXJ

03 & 04 relate to 3mm & 4mm, so 03 is the smaller one, probably the illumination, but it'll be obvious when you have a switch in your hand.

The over-heating issue is not altogether "Ob" indicator but also the amount of current the switch carries, because there's no relay, in the circuit, in the conventional sense. I suspect Ralph's hybrid wiring does include a relay, so his switch doesn't have to cope with a constant 8a. Just something else to consider.

robsjeep

If the3 wire connections that attach to the switch are not tight, are dirty, or the crimp to the wire is not tight, not clean, then that connection becomes a high resistance point, that high resistance means heat when turned on. Thus you might be burning up switched because the crimp or connector is dirty or loose, If there are spring metal clips on the connectors, the spring metal will loose its spring temper (i.e. loose its grip ) from over heating, and that means you need to replace, as it will never grip tight again. A new switch will suffer from the bad connection, and soon fail.

So you may need to redo the connector, get a new one and install on the wire that you cut back. The other solution is to install a relay for the fog lamps, the relay will greatly recue the amperage handled by the switch, and with low amps flowing thru the switch, the over heating will be greatly reduced


So inspect the connector pins, and the crimp to the wires for signs of looseness,, dirty, discoloration from heat, loss of spring tension, if bad replace the connector. and or add a relay for the fog lamps.

UKXJ

Can't say I've ever had that problem in this application - but, as a general principle, that's absolutely right. Might as well check/remedy any such issues while you're in there.

As for the relay, for sure, for sure; I would suggest fitting one, & uprated wires, in any event - especially on a Jeep!

ArklahomaCowboy

That was fun reading all the replies. Great stuff! It never occurred to me that tiny switch was carrying a constant 8 amp load. Makes no sense to me to expect it to carry it for long. I still think poor system design.

I also hadn’t thought about bad crimp(s). It’s all OEM wiring. I will clean up the plug really well with some dielectric gel.

I’m probably going to go with a relay and new switch.

Great discussion!🤓

XJlimitedx99

I feel like its worth mentioning again that switch and circuit were not intended to be used full time. Fog lights are only meant to be used in low speed, low visibility conditions. Think fog that is dense enough that you can't do 25 mph because your low beams are reflecting back too much. If you can comfortably do the speed limit, the fog lights are actively hurting your visibility.

I work in automotive lighting and I guess have become a stickler for lights. Its a pet peeve of mine to see people that run around with their fogs on 100% of the time. Fog lights detract from your visibility by lighting up the area directly in front of you which gives the illusion of better visibility but really is just constricting your pupils which gives worse visibility further down the road, where it matters. Its the equivalent of having a big screen on full brightness inside the cab, which also bothers the crap out of me.

Everyone argues fogs are good for spotting wildlife on the side of the road. That is true to an extent, but at speeds over ~25 mph I don't feel it makes a difference. Fogs throw about 25 ft. Human reaction time is about 0.250 seconds. At 35 mph you're covering 50 feet per second so you would have about 1/4 second to react before you reach the animal. In that time either the animal is staying where it is and you drive by, or it is jumping in front of you. Figure you slam on the brakes the moment you see it and you can slow down at an average rate (quick google shows 15 fps/s), you lose about 2.5 mph in that time and hit the animal at 32.5 mph instead of 35 mph. That is negating the effect of constricted pupils.

Sorry for the rant. I just sat down at work and apparently its Friday because I'm writing a novel about fog lights to people on the internet who are gonna think I'm a nerd. If you use fogs because they look cool then all the power to you. They're certainly a style thing. FWIW I have two fogs wired up with a relay (custom circuit) using the OEM switch, and I do occasionally use the fogs in my daily in inclement weather.

tlc1976

Fogs are nice to use as DRLs. To improve presence to other traffic, without burning up the life of all the other lights that aren’t needed at the time. Of course this is if you run fogs on an independent circuit.

jvmarino

Following up on what XJlimitedx99 said above, fog lights are not meant to run all the time and don't have the bulb life that a standard headlight has. That is why when people run them all the time (also a pet peeve for me), they usually have them burn out and you see their cars with a burned out fog light. I have OEM fog lights on most of my cars, but can count on 1 hand the amount of times I have used them.

Driving lights are a different story when it comes to using them for seeing better at night, but I believe they are not legal for road use in USA. Not that it really matters now that all these new cars have HID/LED lights that blind everyone around them. In the wintertime when the commute home from work is usually in the dark, my eyes are in pain by the time I get home from these lights either behind me or coming at me. No idea why DOT allowed them to be used.